What is notable about the current Lib Dem party is that it can be split into two distinct factions. The first is an 'Orange Book', right-wing faction, who occupy most of the leadership positions in the parliamentary party and encompass Clegg, Vince Cable (to a certain extent), Douglas Alexander and the likes of David Laws. This faction has been notable for its eagerness to adopt neo-liberal economic policies previously (until Cameron dropped the pretence of being vaguely moderate) the preserve of the right of the Tory Party. So, from university funding, through to NHS privatisation and local government finance, this wing is a leading part of the neo-liberal assault on the public realm.
The second faction as what can best be described as the ostrich faction. This wing includes those previously seen as soft-left, such as the likes of Simon Hughes and Chris Huhne. This group are both notable either for inexplicably trying to defend positions they obviously don't agree with or for diving for cover whenever a contentious issue arises.
In response, since the election the broader Liberal Democrat Party has split into four sections: the two above, a third faction desperately trying to turn the party left and a much larger forth section... those that have walked away. The Barnsely Central result demonstrates just how much larger the latter is.